Playground environments present unique design challenges. Playgrounds are designed to be low maintenance, sometimes with years between part replacement. Playgrounds also are designed to withstand high temperature differentials—snow and ice in the winter as well as extreme heat and precipitation in the summer. Playgrounds are also often designed for use by children with little or no supervision. Children learn important mobility and interpersonal skills on the playground. For that reason, it is important that interactive structures within playground environments be accessible by children with a wide variety of abilities. However, above all, it is imperative that playground structures and devices are safe for their users.